averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-14 20:36:38 +01:00
Code Issues Packages Projects Releases Wiki Activity

AST: Don't call ProtocolDecl::getSuperclass() in lookupExistentialConformance()

Browse Source
This commit is contained in:
Slava Pestov
2024-03-20 15:32:25 -04:00
parent e3d434fbbe
commit bc85d66b96
2 changed files with 37 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
lib/AST/ConformanceLookup.cpp
View File

@@ -76,8 +76,8 @@ ModuleDecl::lookupExistentialConformance(Type type, ProtocolDecl *protocol) {
return type;
};
auto lookupSuperclassConformance = [&](ExistentialLayout &layout) {
if (auto superclass = layout.explicitSuperclass) {
auto lookupSuperclassConformance = [&](Type superclass) {
if (superclass) {
if (auto result =
lookupConformance(superclass, protocol, /*allowMissing=*/false)) {
if (protocol->isSpecificProtocol(KnownProtocolKind::Sendable) &&
@@ -101,7 +101,7 @@ ModuleDecl::lookupExistentialConformance(Type type, ProtocolDecl *protocol) {
auto layout = type->getExistentialLayout();
if (llvm::all_of(layout.getProtocols(),
[](const auto *P) { return P->isMarkerProtocol(); })) {
if (auto conformance = lookupSuperclassConformance(layout)) {
if (auto conformance = lookupSuperclassConformance(layout.explicitSuperclass)) {
return ProtocolConformanceRef(
ctx.getInheritedConformance(type, conformance.getConcrete()));
}
@@ -113,15 +113,12 @@ ModuleDecl::lookupExistentialConformance(Type type, ProtocolDecl *protocol) {
auto layout = type->getExistentialLayout();
// Due to an IRGen limitation, witness tables cannot be passed from an
// existential to an archetype parameter, so for now we restrict this to
// @objc protocols and marker protocols.
// If the existential contains non-@objc protocols and the protocol we're
// conforming to needs a witness table, the existential must have a
// self-conformance witness table. For now, Swift.Error is the only one.
if (!layout.isObjC() && !protocol->isMarkerProtocol()) {
auto constraint = getConstraintType();
// There's a specific exception for protocols with self-conforming
// witness tables, but the existential has to be *exactly* that type.
// TODO: synthesize witness tables on-demand for protocol compositions
// that can satisfy the requirement.
// The existential has to be *exactly* that type.
if (protocol->requiresSelfConformanceWitnessTable() &&
constraint->is<ProtocolType>() &&
constraint->castTo<ProtocolType>()->getDecl() == protocol)
@@ -130,31 +127,23 @@ ModuleDecl::lookupExistentialConformance(Type type, ProtocolDecl *protocol) {
return ProtocolConformanceRef::forInvalid();
}
// If the existential is class-constrained, the class might conform
// concretely.
if (auto conformance = lookupSuperclassConformance(layout))
return conformance;
// Otherwise, the existential might conform abstractly.
// The existential might conform abstractly.
for (auto protoDecl : layout.getProtocols()) {
// If we found the protocol we're looking for, return an abstract
// conformance to it.
if (protoDecl == protocol)
return ProtocolConformanceRef(ctx.getSelfConformance(protocol));
// If the protocol has a superclass constraint, we might conform
// concretely.
if (auto superclass = protoDecl->getSuperclass()) {
if (auto result = lookupConformance(superclass, protocol))
return result;
}
// Now check refined protocols.
if (protoDecl->inheritsFrom(protocol))
return ProtocolConformanceRef(ctx.getSelfConformance(protocol));
}
// If the existential is class-constrained, the class might conform
// concretely.
if (auto conformance = lookupSuperclassConformance(layout.getSuperclass()))
return conformance;
// We didn't find our protocol in the existential's list; it doesn't
// conform.
return ProtocolConformanceRef::forInvalid();

24
test/Generics/marker_self_conformance.swift Normal file
View File

@@ -0,0 +1,24 @@
// RUN: %target-typecheck-verify-swift
@_marker protocol Q {}
struct G<T: Q> {}
typealias A1 = G<any Q>
//
class C: Q {}
typealias A2 = G<C>
//
protocol Q2: Q {}
typealias A3 = G<any Q2>
//
protocol P1: C {}
protocol P2 where Self: C {}
typealias A4 = G<any P1>
typealias A5 = G<any P2>